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High Efficiency 12V White LED Driver - DC powered LED lighting circuits can vary from trivial single LEDs with series resistors and LEDs with simple analog current regulators to more complicated switching power supply circuits such as this project. There is a tradeoff between simplicity and circuit capabilities. This more complex circuit adds features such as regulated light level across a wide range of input voltages and automatic circuit shutoff on low input voltage. __ Designed by G. Forrest Cook High Efficiency ThinSOT White LED Driver Features Internal Switch & Schottky Diode - DN325 Design Notes__ Linear Technology/Analog Devices
High Efficiency White LED Driver Guarantees Matching LED Brightness - DN267 Design Notes__ Linear Technology/Analog Devices
High Efficienty ThinSOT White LED Driver Feature Switche & Schottky Diode - Magazine Design Idea
May 2004__ Linear Technology/Analog Devices
High Efficienty White LED Driver Guarantees Matching LED Brightness - Design Notes 267__ Linear Technology/Analog Devices
High Intensity Line Powered LED Flasher - There are times when you would like to generate an intensely bright flash of light using electrical power from the AC line. The circuit below can drive a one to three watt power LED with about 350ma of peak current. Since the circuit drives the LED with. . . Circuit by Dave Johnson P.E.-December, 2008
IC Controlled Emergency Light with Charger - White LEDs are replacing the conventional incandescent and fluorescent bulbs due to their high power efficiency and low operating voltage. These can be utilised optimally for emergency lamp and vehicle turning...__ Electronics Projects for You
LED Array powered by 24 VA - C - 24vac is a popular voltage. It is often used in low voltage lighting systems and industrial controls. It is much less dangerous than 120vac/240vac line voltages. This hobby circuit below is one method to efficiently power a cluster of 7 white LEDs from 24vac. . . . Hobby Circuit designed by David Johnson P.E.-December, 2009
LED dimmer uses only two lines - 03/21/02 EDN-Design Ideas The circuit in Figure 1provIdeas 32 steps of brightness control-from 0 to 100%-for a backlight or instrument panel, using just two general-purpose-microprocessor signals. In addition, the circuit requires little board space, because it uses only three SOT-23s and one µMax package Design by Jerry Wasinger, WallyWare Inc, Norcross, GA
LED Driver-Wireless - The circuit solves this problem by sending power to the LED through the plastic, using a magnetic coupling technique. The circuit below can route power through plastic enclosures as thick as Ľ inch. The circuit will not work through metal boxes . . . Hobby Circuit designed by Dave Johnson P.E.-November, 2008
LED Flasher - Based on the MAX660, designed to power three 3mm/5mm white LED's from 3V (1.5V min) , intended for replacing incandescent bulbs in small torches.) __ Designed by Submitted Andre
LED Flasher-Wig/Wag - This simple circuit will flash two LEDs in an alternating fashion . . . Hobby Circuit designed by David Johnson P.E.-December, 2004
LED Flasher-Wireless Circuit - When you would like to flash a LED through a thick plastic case without wires, use this hobby circuit. It performs this feat. It draws about 300ua of average current at 5v. It can be powered from a supply ranging from 3v to 6v . . . Hobby Circuit designed by Dave Johnson P.E.-January, 2011
LED Moving Sign 7 x 10 - This sign uses two LED arrays to form a 7 X 10 matrix. It produces moving messages or animations stored in an EPROM. It uses no microprocessor. As in most electric signs, the LEDs are matrixed, and strobed very quickly. __ Designed by Bob Blick
LED Strings Powered by AC Line - This shows 4 different ways to string white LEDs that are powered by a 120vac or 240vac power line. __ Designed by Ken Schultz, drawn Dave Johnson 12.18.2004
LED white light bulb - mains powered, no loss power supply, ultra green __ Designed by Thomas Scherrer OZ2CPU
Light a white LED from half a cell - 12-Jun-03 EDN-Design Ideas Whether you use them as indicators or to provide illumination, LEDs are hard to beat in efficiency, reliability, and cost. White LEDs are rapidly gaining popularity as sources of illumination, as in LCD backlights, but with forward voltages typically ranging from 3 to 5V, operating them from a single cell presents obvious difficulties Design by Anthony Smith, Scitech, Biddenham, Bedfordshire, UK
Li-Ion to Six White LEDs & OLED/LCD Bias - The LT3498 can provide both the positive bias voltage required for OLED or CCD bias as well as drive multiple white LEDs for display backlighting__ Linear Technology/Analog Devices App Note, Mar 24th 2010
Li-Ion to Two White LEDs & OLED/LCD Bias - The LT3498 can provide both the positive bias voltage required for OLED or CCD bias as well as drive multiple white LEDs for display backlighting__ Linear Technology/Analog Devices App Note, Mar 24th 2010
Line Powered High Intensity LED Flasher - There are times when you would like to generate an intensely bright flash of light using electrical power from the AC line. The circuit below can drive a one to three watt power LED with about 350ma of peak current. Since the circuit drives the LED with . . . Hobby Circuit designed by David A. Johnson P.E.-December, 2008
Line Powered White LED Array - There has been a lot of excitement lately in the lighting industry. Some companies are beginning to manufacture general lighting fixtures, which replace incandescent and fluorescent lamps, using LED lights. When proper heat management is designed. . . Circuit by David Johnson P.E.-February, 2010
Line Powered White LEDs - The LED circuit above is an example of using 25 white LEDs in series connected to the 120VAC line. It can be modified for more or less LEDs by changing the R value. The exact resistance value will depend on the particular LEDs used. In operation, a DC voltage of around 170 is produced from the bridge rectifier and 50uF capacitor. The capacitor value is not critical __ Designed by Bill Bowden
Linear Constant Current LED Lamp Dimmer - This circuits drives 24 white light LEDs with an adjustable constant current
Multipurpose White-LED Light - Standard fluorescent lamps and their smaller versions called compact fluorescent lamps (CFLs) radiate light in all directions (360°) and tend to increase the room temperature. In emergency lights using these lamps,...__ Electronics Projects for You
Night Light from White LED - As many of you know, I have a pet peeve with poorly made LED night lights. Often, the light from the LED quickly fades, so within months, the light is useless. I have posted several versions of modified night lights using higher quality components. . . Circuit by Dave Johnson P.E.-November, 2008
Not 1 But 2 White LED Torches to build - These LED torches produce a beautiful even spread of white light which is quite different from that of conventional torches using Krypton bulbs.__ SiliconChip
One Cell Flashes White LED - 12/11/03 EDN-Design Ideas Many portable appliances and other products that must operate from a single cell are restricted to working at very low voltages. It is thus difficult to drive white LEDs that typically have a forward voltage of 3 to 5V. The ability Design by Anthony Smith, Scitech, Biddenham, Bedfordshire, UK
One NiMH
Cell powers White LED - There are a lot of white LED driver circuits floating around. A popular circuit called the “Joule Thief” can drive one white LED from a single 1.2v or 1.5v battery cell. Most of these circuits use one or two transistors to form a voltage boost circuit . . . Hobby Circuit designed by Dave Johnson P.E.-September, 2009
One-Watt White LED Night Light - As many of you know, I have a pet peeve with poorly made LED night lights. Often, the light from the LED quickly fades, so within months, the light is useless. I have posted several versions of modified night lights using higher quality components. This circuit is yet another version, which produces much more light than those other designs. . . . Hobby Circuit designed by David Johnson P.E.-November, 2008
Optical feedback extends white LEDs' operating life - 01/18/07 EDN-Design Ideas PWM-controller loop stabilizes light output Design by Bjoy Santos, Intersil Corp, Milpitas, CA |
